One thing was set in stone at last season's trade deadline:
Ainge is never going to "build around" Lauri. He sees him as a Robin. The decision not to go for the playoffs was, among other things, a giant vote of no confidence. In essence, DA was telling Lauri, "My guy, you're not gonna be good enough to carry a team as a top dog in the long run, so let's not even start pretending."
Now, that doesn't mean Danny won't gladly hand LM an absolutely huge extension. Of course he will. But as the face of the franchise, Lauri's a placeholder. That's just how it is, and Ainge may turn out to be right in the end. Personally, I think tanking the rest of the season did a huge amount of damage on several fronts and we accomplished little.
The trade deadline, coupled with Lauri's emergence, was a chance to accelerate the rebuild in a way that's incredibly rare without hitting big in the draft. It was a chance to streamline and improve the team and give it more respectability, all in one fell swoop. We would have been starting this season without a stupid guard logjam, and perhaps with an actual young co-star for Lauri on the roster.
But Danny didn't see it that way.